Making a plugin from objective C code

I have some objective - c code below, i want to call from Unity, i know i need to make a .m and .h file but im not to sure about how to go about it, i dont have much experience in objective-c , what would be the content , imports etc for a .m and .h file that i would put in the assets/plugins/ios folder?

-(IBAction) sendInAppSMS:(id) sender
	MFMessageComposeViewController *controller = [[[MFMessageComposeViewController alloc] init] autorelease];
	if([MFMessageComposeViewController canSendText])
		controller.body = @"Hello from Mugunth";
		controller.recipients = [NSArray arrayWithObjects:@"12345678", @"87654321", nil];
		controller.messageComposeDelegate = self;
		[self presentModalViewController:controller animated:YES];

This is the page that helps you create an iOS plugin:

or Mac OS X: